這段程式碼出自《JavaScript高階程式設計 第三版》第521頁

function creatXHR(){
  if (typeof XMLHttpRequest != "undefined") {
    return new XMLHttpRequest();
  } else if {
    if (typeof arguments.callee.activeXString != "undefined") {
      var versions = [ "MSXML2.XMLHttp.6.0", "MSXML2.XMLHttp.3.0", "MSXML2.XMLHttp"], i, len;
      for (i = 0, len = versions.length; i < len; i++) {
        try {
          new ActiveXObject(versions[i]);
          arguments.callee.activeXString = versions[i];
          break;
        } catch (ex) {
          // 跳過
        }
      } 
    }
    returm new ActiveeXObject(arguments.callee.activeXString);
  } else {
    throw new Error("No XHR object available.");
  }
}